[libvirt] [PATCH 04/14] Don't link virt-login-shell against libvirt.so (CVE-2013-4400)
Daniel P. Berrange
berrange at redhat.com
Mon Oct 21 13:12:39 UTC 2013
From: "Daniel P. Berrange" <berrange at redhat.com>
The libvirt.so library has far too many library deps to allow
linking against it from setuid programs. Those libraries can
do stuff in __attribute__((constructor) functions which is
not setuid safe.
The virt-login-shell needs to link directly against individual
files that it uses, with all library deps turned off except
for libxml2 and libselinux.
Create a libvirt-setuid-rpc-client.la library which is linked
to by virt-login-shell. A config-post.h file allows this library
to disable all external deps except libselinux and libxml2.
Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
Makefile.am | 1 +
config-post.h | 44 ++++++++++++++++++
configure.ac | 1 +
daemon/Makefile.am | 1 +
examples/domain-events/events-c/Makefile.am | 3 +-
examples/hellolibvirt/Makefile.am | 2 +-
examples/openauth/Makefile.am | 2 +-
gnulib/lib/Makefile.am | 2 +-
python/Makefile.am | 1 +
src/Makefile.am | 72 +++++++++++++++++++++++++++++
src/libvirt.c | 36 +++++++++------
tools/Makefile.am | 9 +++-
12 files changed, 153 insertions(+), 21 deletions(-)
create mode 100644 config-post.h
diff --git a/Makefile.am b/Makefile.am
index f3b5cd2..192a378 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -31,6 +31,7 @@ XML_EXAMPLES = \
test/*.xml storage/*.xml)))
EXTRA_DIST = \
+ config-post.h \
ChangeLog-old \
libvirt.spec libvirt.spec.in \
mingw-libvirt.spec.in \
diff --git a/config-post.h b/config-post.h
new file mode 100644
index 0000000..d371e8c
--- /dev/null
+++ b/config-post.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Since virt-login-shell will be setuid, we must do everything
+ * we can to avoid linking to other libraries. Many of them do
+ * unsafe things in functions marked __atttribute__((constructor)).
+ * The only way avoid to avoid such deps is to re-compile the
+ * functions with the code in question disabled, and for that we
+ * must override the main config.h rules. Hence this file :-(
+ */
+
+#ifdef LIBVIRT_SETUID_RPC_CLIENT
+# undef HAVE_LIBDEVMAPPER_H
+# undef HAVE_LIBNL
+# undef HAVE_LIBNL3
+# undef HAVE_LIBSASL2
+# undef WITH_CAPNG
+# undef WITH_CURL
+# undef WITH_DTRACE_PROBES
+# undef WITH_GNUTLS
+# undef WITH_MACVTAP
+# undef WITH_NUMACTL
+# undef WITH_SASL
+# undef WITH_SSH2
+# undef WITH_VIRTUALPORT
+# undef WITH_YAJL
+# undef WITH_YAJL2
+#endif
diff --git a/configure.ac b/configure.ac
index 1993fab..1c5b168 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,6 +20,7 @@ AC_INIT([libvirt], [1.1.3], [libvir-list at redhat.com], [], [http://libvirt.org])
AC_CONFIG_SRCDIR([src/libvirt.c])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_HEADERS([config.h])
+AH_BOTTOM([#include <config-post.h>])
AC_CONFIG_MACRO_DIR([m4])
dnl Make automake keep quiet about wildcards & other GNUmake-isms; also keep
dnl quiet about the fact that we intentionally cater to automake 1.9
diff --git a/daemon/Makefile.am b/daemon/Makefile.am
index 46c766c..e5c5db8 100644
--- a/daemon/Makefile.am
+++ b/daemon/Makefile.am
@@ -18,6 +18,7 @@
INCLUDES = \
-I$(top_builddir)/gnulib/lib -I$(top_srcdir)/gnulib/lib \
+ -I$(top_srcdir) \
-I$(top_builddir)/include -I$(top_srcdir)/include \
-I$(top_builddir)/src -I$(top_srcdir)/src \
-I$(top_srcdir)/src/util \
diff --git a/examples/domain-events/events-c/Makefile.am b/examples/domain-events/events-c/Makefile.am
index 0646aee..86500a0 100644
--- a/examples/domain-events/events-c/Makefile.am
+++ b/examples/domain-events/events-c/Makefile.am
@@ -15,7 +15,8 @@
## <http://www.gnu.org/licenses/>.
INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include \
- -I$(top_builddir)/gnulib/lib -I$(top_srcdir)/gnulib/lib
+ -I$(top_builddir)/gnulib/lib -I$(top_srcdir)/gnulib/lib \
+ -I$(top_srcdir)
noinst_PROGRAMS = event-test
event_test_CFLAGS = $(WARN_CFLAGS)
event_test_SOURCES = event-test.c
diff --git a/examples/hellolibvirt/Makefile.am b/examples/hellolibvirt/Makefile.am
index 060cc71..55ea972 100644
--- a/examples/hellolibvirt/Makefile.am
+++ b/examples/hellolibvirt/Makefile.am
@@ -14,7 +14,7 @@
## License along with this library. If not, see
## <http://www.gnu.org/licenses/>.
-INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include
+INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include -I$(top_srcdir)
noinst_PROGRAMS = hellolibvirt
hellolibvirt_CFLAGS = $(WARN_CFLAGS)
hellolibvirt_SOURCES = hellolibvirt.c
diff --git a/examples/openauth/Makefile.am b/examples/openauth/Makefile.am
index 1eb23fc..7bb8604 100644
--- a/examples/openauth/Makefile.am
+++ b/examples/openauth/Makefile.am
@@ -14,7 +14,7 @@
## License along with this library. If not, see
## <http://www.gnu.org/licenses/>.
-INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include
+INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include -I$(top_srcdir)
noinst_PROGRAMS = openauth
openauth_CFLAGS = $(WARN_CFLAGS)
openauth_SOURCES = openauth.c
diff --git a/gnulib/lib/Makefile.am b/gnulib/lib/Makefile.am
index e27c658..f098e82 100644
--- a/gnulib/lib/Makefile.am
+++ b/gnulib/lib/Makefile.am
@@ -27,4 +27,4 @@ noinst_LTLIBRARIES =
include gnulib.mk
-INCLUDES = $(GETTEXT_CPPFLAGS)
+INCLUDES = -I$(top_srcdir) $(GETTEXT_CPPFLAGS)
diff --git a/python/Makefile.am b/python/Makefile.am
index f327300..c9c2a8b 100644
--- a/python/Makefile.am
+++ b/python/Makefile.am
@@ -20,6 +20,7 @@ INCLUDES = \
$(PYTHON_INCLUDES) \
-I$(top_builddir)/gnulib/lib \
-I$(top_srcdir)/gnulib/lib \
+ -I$(top_srcdir) \
-I$(top_builddir)/src \
-I$(top_srcdir)/src \
-I$(top_srcdir)/src/util \
diff --git a/src/Makefile.am b/src/Makefile.am
index a9b6d58..9dab4df 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -21,6 +21,7 @@
# that actually use them. Also keep GETTEXT_CPPFLAGS at the end.
INCLUDES = -I../gnulib/lib \
-I$(top_srcdir)/gnulib/lib \
+ -I$(top_srcdir) \
-I../include \
-I$(top_srcdir)/include \
-I$(top_srcdir)/src/util \
@@ -1966,6 +1967,77 @@ libvirt_lxc_la_LDFLAGS = \
libvirt_lxc_la_CFLAGS = $(AM_CFLAGS)
libvirt_lxc_la_LIBADD = libvirt.la $(CYGWIN_EXTRA_LIBADD)
+# Since virt-login-shell will be setuid, we must do everything
+# we can to avoid linking to other libraries. Many of them do
+# unsafe things in functions marked __atttribute__((constructor)).
+# This library is built to include the bare minimum required to
+# have a RPC client for local UNIX socket access only. We use
+# the ../config-post.h header to disable all external deps that
+# we don't want
+if WITH_LXC
+noinst_LTLIBRARIES += libvirt-setuid-rpc-client.la
+
+libvirt_setuid_rpc_client_la_SOURCES = \
+ util/viralloc.c \
+ util/virbitmap.c \
+ util/virbuffer.c \
+ util/vircommand.c \
+ util/virconf.c \
+ util/virerror.c \
+ util/virevent.c \
+ util/vireventpoll.c \
+ util/virfile.c \
+ util/virhash.c \
+ util/virhashcode.c \
+ util/virjson.c \
+ util/virlog.c \
+ util/virobject.c \
+ util/virpidfile.c \
+ util/virprocess.c \
+ util/virrandom.c \
+ util/virsocketaddr.c \
+ util/virstoragefile.c \
+ util/virstring.c \
+ util/virtime.c \
+ util/virthread.c \
+ util/virtypedparam.c \
+ util/viruri.c \
+ util/virutil.c \
+ util/viruuid.c \
+ conf/domain_event.c \
+ rpc/virnetsocket.c \
+ rpc/virnetsocket.h \
+ rpc/virnetmessage.h \
+ rpc/virnetmessage.c \
+ rpc/virkeepalive.c \
+ rpc/virkeepalive.h \
+ rpc/virnetclient.c \
+ rpc/virnetclientprogram.c \
+ rpc/virnetclientstream.c \
+ rpc/virnetprotocol.c \
+ remote/remote_driver.c \
+ remote/remote_protocol.c \
+ remote/qemu_protocol.c \
+ remote/lxc_protocol.c \
+ datatypes.c \
+ libvirt.c \
+ libvirt-lxc.c \
+ $(NULL)
+
+libvirt_setuid_rpc_client_la_LDFLAGS = \
+ $(AM_LDFLAGS) \
+ $(LIBXML_LIBS) \
+ $(SELINUX_LIBS) \
+ $(NULL)
+libvirt_setuid_rpc_client_la_CFLAGS = \
+ -DLIBVIRT_SETUID_RPC_CLIENT \
+ -I$(top_srcdir)/src/conf \
+ -I$(top_srcdir)/src/rpc \
+ $(AM_CFLAGS) \
+ $(SELINUX_CFLAGS) \
+ $(NULL)
+endif WITH_LXC
+
lockdriverdir = $(libdir)/libvirt/lock-driver
lockdriver_LTLIBRARIES =
diff --git a/src/libvirt.c b/src/libvirt.c
index 7fa675a..7ceec30 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -446,40 +446,46 @@ virGlobalInit(void)
goto error;
/*
+ * Note we must avoid everything except 'remote' driver
+ * for virt-login-shell usage
+ */
+#ifndef LIBVIRT_SETUID_RPC_CLIENT
+ /*
* Note that the order is important: the first ones have a higher
* priority when calling virConnectOpen.
*/
-#ifdef WITH_TEST
+# ifdef WITH_TEST
if (testRegister() == -1)
goto error;
-#endif
-#ifdef WITH_OPENVZ
+# endif
+# ifdef WITH_OPENVZ
if (openvzRegister() == -1)
goto error;
-#endif
-#ifdef WITH_VMWARE
+# endif
+# ifdef WITH_VMWARE
if (vmwareRegister() == -1)
goto error;
-#endif
-#ifdef WITH_PHYP
+# endif
+# ifdef WITH_PHYP
if (phypRegister() == -1)
goto error;
-#endif
-#ifdef WITH_ESX
+# endif
+# ifdef WITH_ESX
if (esxRegister() == -1)
goto error;
-#endif
-#ifdef WITH_HYPERV
+# endif
+# ifdef WITH_HYPERV
if (hypervRegister() == -1)
goto error;
-#endif
-#ifdef WITH_XENAPI
+# endif
+# ifdef WITH_XENAPI
if (xenapiRegister() == -1)
goto error;
-#endif
-#ifdef WITH_PARALLELS
+# endif
+# ifdef WITH_PARALLELS
if (parallelsRegister() == -1)
goto error;
+# endif
#endif
#ifdef WITH_REMOTE
if (remoteRegister() == -1)
diff --git a/tools/Makefile.am b/tools/Makefile.am
index d8c912f..256a8f3 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -153,6 +153,11 @@ virt_host_validate_CFLAGS = \
$(COVERAGE_CFLAGS) \
$(NULL)
+# Since virt-login-shell will be setuid, we must do everything
+# we can to avoid linking to other libraries. Many of them do
+# unsafe things in functions marked __atttribute__((constructor)).
+# This we statically link to a library containing only the minimal
+# libvirt client code, not libvirt.so itself.
virt_login_shell_SOURCES = \
virt-login-shell.c
@@ -163,11 +168,11 @@ virt_login_shell_LDFLAGS = \
virt_login_shell_LDADD = \
$(STATIC_BINARIES) \
$(PIE_LDFLAGS) \
- ../src/libvirt.la \
- ../src/libvirt-lxc.la \
+ ../src/libvirt-setuid-rpc-client.la \
../gnulib/lib/libgnu.la
virt_login_shell_CFLAGS = \
+ -DLIBVIRT_SETUID_RPC_CLIENT \
$(WARN_CFLAGS) \
$(PIE_CFLAGS) \
$(COVERAGE_CFLAGS)
--
1.8.3.1
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